del.icio.us is a collection of favorites – yours and everyone else’s. You can use del.icio.us to:

Keep links to your favorite articles, blogs, music, reviews, recipes, and more, and access them from any computer on the web.

Share favorites with friends, family, coworkers, and the del.icio.us community.

Discover new things. Everything on del.icio.us is someone’s favorite — they’ve already done the work of finding it. So del.icio.us is full of bookmarks about technology, entertainment, useful information, and more. Explore and enjoy.

del.icio.us is a social bookmarking website — the primary use of del.icio.us is to store your bookmarks online, which allows you to access the same bookmarks from any computer and add bookmarks from anywhere, too. On del.icio.us, you can use tags to organize and remember your bookmarks, which is a much more flexible system than folders.

Explanation of tags in de.licious:

You can use tags describing an article or website’s subject, location, name, category, people, places, ideas — pretty much anything you can think of. The more tags the better! (Well, most people use from one or two up to five or six tags for an item.)

Coolinarika is Croatian web portal of food company Podravka. It is virtual cookbook and people can join and participate with adding their own receipts. They also use tagging as a way of organizing content.

No matter which content people share and use social networking became way of life. Everyone wants to give access to their content and people like to use tags and categories as their way of marking and describing of content.
That is today and the future of Internet.